A liquid crystal displays (“LCD”) is a well-known display technology. Unpolarized or linearly polarized light is incident on the LCD. A first polarizer polarizes the light. Liquid crystals inside the display rotate the polarization state of the light based on the voltage applied. A final output polarizer only transmits one polarization direction. Thus, the amount of polarization rotation modulates the brightness of the light to create the desired image. This is done using Malus' Law where I=Io*cos2(θ). Io is the incident power, θ is the angle between the rotated light and the output polarizer, and I is the output power. Measuring the resulting image that goes to the observer is challenging in a test environment. The manufacturers of these parts use human operators with optical projectors to enlarge and assess the image performance from the LCD for these small display panels.
Liquid crystal on silicon (“LCOS”) is a display technology that uses polarized light to create an image. As an example, when p-polarized light is used to illuminate an LCOS display, the LCOS changes the incident p-polarization into a reflected mix of p-polarization and s-polarization based on the desired pixel intensity. The s-polarized portion is transmitted to the user using a polarizing beam splitter (“PBS”) while the p-polarized portion is thrown away. Again, measuring the resulting image that goes to the observer is challenging in a test environment. The manufacturers of these parts also use human operators with optical projectors to enlarge and assess the image performance from the LCOS.